AW: [ECI-EN] Re: Fastest way to find densities for ISO 12647-2 implementation?

The problem of non-constant solid density is always there, it can be minimised, however, by an adequate setting of the onset of the reciprocating inking roller and, if at all possible, by using a test forme with homogeneous ink demand over the width of the forme. If you care to measure tone value increase in more than one place along the printing direction you will be surprised how much it can vary, so better take averages and do not expect precision results. Regards Mit freundl. Gru?en Fred Dolezalek Dr. Friedr. Dolezalek FOGRA, Graphic Techn. FOGRA Forschungsges. Research Association Druck e.V. dolezalek at fogra.org Tel. +49-89-43182-311, Fax +49-89-43182-100 PO. Box 80 04 69, D-81604 Muenchen, Germany Streitfeldstr. 19, D-81673 Muenchen, Germany -----Ursprungliche Nachricht----- Von: eci-en-admin(a)lists.transmedia.de [mailto:eci-en-admin@lists.transmedia.de]Im Auftrag von Yann Bouckaert Gesendet: 27. August 2004 10:25 An: eci-en(a)lists.transmedia.de Betreff: [ECI-EN] Re: Fastest way to find densities for ISO 12647-2 implementation? Hello, Thanks for answers regarding finding the appropriate density. The density wedge is the way to go it seems. Another question comes to my mind: would you put process colour step wedges on the same sheet to determine the dotgain, or in a next printing run with the same density across the width of the sheet? I'm asking this, because when you take the route of the density wedge to find the appropriate density, you must put the step wedges in one row, perpendicular to the density wedge. Say you find that zone 14 has the best density for cyan, you then look in that particular zone for the cyan step wedge to determine the corresponding dotgain. But: density can vary across the sheet in the printing direction. You risk writing down dotgain results for an area that does not have the same density as at the bottom of the page. I recently measured M 1.54 at the bottom of a page, M 1.44 in the middle op the page where the step wedge was, and 1.54 again at the top. Dotgain for M at the bottom was 19%, and 17% in the middle. No big deal maybe? I realise that after putting appropriate correction curves in the rip to compensate for extra dotgain, a new print run is needed to verify the results. Sorry to bother you with all this, but practical advice is hard to find. Have a nice weekend, Yann Bouckaert Sagam NV Drongen, Belgium _______________________________________________ ECI-EN mailing list ECI-EN(a)lists.transmedia.de http://lists.transmedia.de/mailman/listinfo/eci-en